No-tools chair seat assembly

ABSTRACT

A seat assembly is constructed such that the consumer can secure the base to the seat without using any tools. A consumer inserts a tab at one end of a mounting plate into a slot at one end of a base plate secured to a seat. An opening on the mounting plate is moved to receive a latch on the base plate. An actuator allows the consumer to retract a spring-loaded latch bolt on the latch to move the latch through the opening. The spring-loaded latch bolt then secures the mounting plate against the base plate. In order to limit the ability of the mounting plate to slide with respect to the base plate, projections on the base plate pass through mounting plate apertures. The seat assembly may also include controls for seat height and seat reclining resistance, as well as a seat back.

BACKGROUND OF THE INVENTION

The present invention relates to ready to assemble furniture and more particularly to a ready to assemble chair seat which can be assembled by the customer without the use of any tools.

To conserve shipping space and reduce shipping costs, it is known to ship furniture products in a disassembled condition. It is particularly desirable to ship rolling office chairs in a disassembled condition as these types of chairs take up a considerable amount of empty space within a shipping box if they are not broken down into their discrete components. However, the drawback is that the customer will need to assemble the chair following purchase. Chair assembly typically involves the use of wrenches or other tools and can prove difficult and time consuming to the customer. In this regard, it is desirable to make the assembly process as simple and as fool proof as possible for the customer.

BRIEF SUMMARY OF THE INVENTION

Accordingly, the present invention provides a rolling office chair assembly where the mechanical components on the underside of the chair seat can be removed from the chair seat for shipping and then re-assembled with the chair seat without the use of any tools. The same mechanism that provides for easy assembly and disassembly also ensures that the chair provides a sturdy seating surface when the chair is assembled.

The chair of the present invention is provided to the customer in separate pieces. The first piece provided by the manufacturer is a seat having a cushioned upper surface and a rigid base plate mounted on its lower surface. The base plate has a spring-loaded latch mechanism at its rear edge and a retention slot at its front edge for attaching the seat of the chair to the base of the chair. The spring-loaded latch mechanism has at least one spring-loaded latch bolt that can be retracted by an actuator.

The second piece provided by the manufacturer is a mounting plate that supports the bulky mechanical components, such as the tension and tilt assemblies. The mounting plate has at least one tab at its front edge to engage the retention slot of the base plate, and at least one catch opening at its rear edge for receiving the spring-loaded latch mechanism of the base plate.

The manufacturer aligns the front edge of the base plate with the front edge of the seat and fastens the base plate to the lower surface of the seat with threaded fasteners. To improve the aesthetic quality of the chair, the manufacturer may cover the base plate with fabric having openings for the latching mechanism and the slot so they remain accessible to the user.

At this point, the chair is ready to be delivered to a customer, who can then assemble the chair without using tools. To assemble the chair, the customer can insert the tab of the mounting plate into the retention slot located toward the front edge of the base plate and push the mounting plate toward the base plate so that the catch opening of the mounting plate is received over a spring-loaded latch mechanism on the rear edge of the base plate. The customer can move an actuator to retract a spring-loaded latch bolt when attaching the mounting plate to the base plate. These steps can be reversed to disassemble the chair.

The manufacturer may include additional structural features. For example, in order to improve the stability of the chair when it is assembled, alignment projections on the base plate can extend through corresponding apertures on the mounting plate. These projections and apertures also make it easier for a customer to align the mounting plate and base plate when assembling the chair.

A center plate secured to the mounting plate serves as an attachment point for additional structural components. For example, the center plate received the gas tube for controlling the height of the seat from the ground. The center plate is also designed such that the spring-loaded catch mechanism does not interfere with the ability of the center plate to receive the gas tube.

Like many office chairs, the seat of this invention has wheels for moving the chair on the floor and a gas cylinder for height adjustment, and is able to recline. A manually accessible tension control knob allows the user to manually adjust a coil spring in order to adjust the resistance to reclining. A person using the chair can rotate a lever to adjust the height of the chair and slide the lever longitudinally to control the ability of the seat to recline.

The exemplary embodiment also includes a seat back, which is secured to a seat back plate. The seat back plate is then secured to the center plate and the base plate so that the seat back may pivot at a different rate than the seat.

Therefore, it is an object of this invention to provide a seat assembly that can be assembled without the use of tools.

It is also an object of this invention to provide a seat assembly that can be assembled by using a tab that engages a slot and a latch that engages a latch opening.

It is also an object of this invention to provide a seat assembly that can be easily disassembled without the use of tools, by using a spring-loaded latch mechanism with a manually operated latch actuator.

It is also an object of this invention to provide a no tools seat assembly that has resistance to sliding between the mounting plate and base plate.

Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which illustrate the best mode presently contemplated for carry out the present invention:

FIG. 1 is a perspective view of a rolling office chair incorporating the no-tools seat assembly of the present invention;

FIG. 2 is a bottom view of the seat showing the no-tools seat assembly;

FIG. 3 is an exploded perspective view thereof:

FIG. 4 is an assembly view thereof showing assembly of the mounting plate with the base plate;

FIG. 5 is a bottom view thereof showing the spring loaded latching mechanism for latching the mounting plate to the base plate; and

FIG. 6 is another bottom view showing a fabric layer secured over the base plate for an improved aesthetic appearance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is directed to a no tools chair seat assembly that allows the user to attach the seat of a chair to the base of a chair without using any tools. FIG. 1 shows one example of a chair 10 that has been fully assembled by a user without using tools. The chair 10 of FIG. 1 includes a seat 12, a back 14, a pair of arms 16, an upper surface of the seat 18, a lower surface of the seat 20 (not visible on FIG. 1), a height adjustment lever 22, a height adjusting gas cylinder 24, legs 26, and wheels 28. The seat may include other adjustments such as tilt adjustments, arm height adjustments, and locking wheels, among other features.

A seat assembly of the present invention may be shipped to a consumer in two main pieces. The first piece comprises a base plate 40 mounted with threaded fasteners 41 on the lower surface 20 of a seat, and the second piece comprises a mounting plate 70 that can support other features of the chair, such as the legs 26. FIGS. 2-4 show how the seat assembly of the present invention may be easily assembled by the user. FIG. 2 shows the base plate 40 mounted on the underside, or lower surface 20, of the seat using threaded fasteners 41.

The base plate 40 and mounting plate 70 have corresponding structures that facilitate securing the base plate to the mounting plate. The base plate 40 is configured to hold the mounting plate 70 by way of a retention slot 44 located towards the front edge 43 of the base plate 40 and a spring-loaded latch mechanism 50 including at least one spring-loaded latch bolt 54 located towards the rear edge 49 of the base plate 40. The mounting plate 70 engages these structures of the base plate by way of a tab 72 at its front edge 73 and a catch opening 74 towards its rear edge 75.

The spring-loaded latch mechanism 50 includes bolts 54 and springs (not shown) that are held by a plastic housing 53 that is secured to the base plate 40 by a second set of fasteners 51. The latch bolts 54 are formed of hardened steel, and are spring biased so they extend outwardly from the latch mechanism housing 53. In order to improve the performance of the latch bolts 54, latch bolt supports 58 on the base plate are stamped and bent 90°. These latch bolt supports 58 provide a strong metal to metal connection with the latch bolts 54.

In order to secure the mounting plate 70 to the base plate 40 of FIG. 3, the user first positions the lower face of the mounting plate 70 at an angle with respect to the base plate 40. The user then inserts the mounting plate tab 72 into the retention slot 44, as shown in FIG. 4. A retention housing 46 is located over the retention slot 44 on the base plate 40. A flexible retention insert 48, which has been factory-mounted to the tab 72, engages the retention housing 46. The exterior of the retention insert 48 and the interior of the retention housing 46 are each designed to have a corresponding radius of curvature so that the retention insert 48 and retention housing 46 can remain in firm rotating engagement once the tab is inserted into the slot and the mounting plate is rotated relative to the base plate, as described below. A tab and slot design that did not feature the curved surfaces of the retention insert 48 and retention housing 46 would form a looser, less stable connection between the tab and slot, rather than the firm connection provided by the present structure. The retention housing 46 supports the retention insert 48, which helps to securely hold the tab 72 in the retention slot 44. The retention insert 48 is made of plastic in one embodiment. The retention insert 48 may be made of a flexible or compressible material that is capable of being deformed when the retention insert 48 is inserted into the retention housing 46, and then continues to apply pressure against the housing to hold it in place. Some embodiments may use a retention insert that is rigid rather than flexible or compressible. For example, the retention insert 48 may be formed on the tab 72 by a metal stamping process.

Next, the user moves the rear edge 75 of the mounting plate 70 towards the rear edge 49 of the base plate 40. As the catch opening 74 is moved over the spring-loaded latch mechanism 50, it will contact the two spring-loaded latch bolts 54 unless they are retracted. The user may operate actuators 56 to retract the spring-loaded latch bolts 54 and slide the catch opening 74 into place, and then release the actuators 56. This may done by moving the actuators 56 toward each other along the actuator paths 57, as shown by the arrows in FIG. 5. The springs in the spring-loaded latch push the latch bolts 54 outward, locking the mounting plate onto the base plate.

Each latch bolt 54 may be designed with a ramped or angled surface such that the edges of the catch opening 74 engage the angled surfaces and push each latch bolt 54 inward as the mounting plate 70 is moved past the latch bolts 54 and towards the base plate 40. Thus, the user would be able to simply push the latch mechanism 50 through the catch opening 74 without manually operating the actuators 56. Once the mounting plate 70 is in facing engagement with the base plate 40, the bolts 54 return to a spring biased position. Thereafter, the edges of the catch opening 74 contact a flat, non-angled surface of the latch bolts 54. Thus, there is no tendency for the mounting plate 70 to release the latch bolts 54 on its own, without a user operating the actuators 56.

In order to increase the stability of the system, metal pins, or projections 42, on the base plate 40 extend through apertures 76 in the mounting plate 70. These projections 42 and apertures 76 limit the ability of the base plate 40 and mounting plate 70 to slide against one another. In FIGS. 2-4, the projections 42 are shown as cylinders and the apertures 76 are shown as circular holes, but these can have different geometry. For example, a detent mechanism could be used instead.

Once the mounting plate 70 is secured to the base plate 40, the consumer may subsequently connect other features of the chair such as a support structure. For example, the center plate 80, which is secured to the mounting plate 70, has a gas cylinder receiver 82, which is capable of receiving a gas tube 24, or gas cylinder, for controlling the height of the seat 12 from the ground. Alternatively, because the gas cylinder 24 does not interfere with the operation or the assembly of the no tools seat plate of the present invention, it may be attached to the mounting plate 70 before or after the mounting plate is secured to the base plate 40.

A height control lever 22 supported by the mounting plate 70 enables the user to depress a button on a gas cylinder 24 and thereby adjust the height of the seat 12. The lever 22 can also be moved longitudinally to control the ability of the seat to recline.

The chair 10 is equipped with additional features that are commonly included on office chairs. For example, the seat can recline, and a spring provides resistance to this reclining motion. A tension control knob 84 allows the user to manually adjust the spring tension, thereby adjusting the seat's resistance to reclining.

The seat assembly may also include a seat back plate for attaching a seat back. In one embodiment, the seat back plate is secured to the center plate 80 and the base plate 40 so that the seat back 14 may pivot at a different rate than the seat 12. A non-pivoting seat back may also be provided, in which case the seat back 14 is bolted directly to the seat 12.

There are many alternative embodiments of the no tools chair seat assembly of the present invention. For example, the latch bolts 54 of FIGS. 2-4 are shown to operate from side to side, but latch bolts that operate in other directions, such as front to rear, may be used.

Although the spring-loaded latch bolt is shown in FIGS. 2-6 as having two latch bolts 54 and two actuators 56, the spring-loaded latch mechanism may include one latch bolt 54 with one actuator 56 configured to retract the latch bolt 54. Alternatively, it may include more than two latch bolts 54 with actuators 56.

Although FIGS. 2-5 show the front edge 43 and rear edge 49 of the base plate aligned with the front edge 23 and rear edge 25 of the lower surface 20, respectively, the base plate 40 may be mounted in different orientations. Different orientations of the base plate with respect to the lower surface of the seat may be used.

To protect the base plate 40 of the chair of the present invention, the lower surface 20 of the seat 12 may be covered in fabric 90, as shown in FIG. 6. This fabric layer 90 includes a hole 92 for the retention slot as well as holes for the latching mechanism 50 and the projections 42. Other parts of the seat 12 may be covered in another fabric 96, and the two fabric layers 90 and 96 may be secured to the seat 12 by staples 94.

It can therefore be seen that the present invention provides a chair that can be assembled by a user without the use of tools. For these reasons, the instant invention is believed to represent a significant advancement in the art which has substantial commercial merit.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims. 

What is claimed is:
 1. A seat assembly comprising: a seat having a lower surface, the lower surface having a front edge and a rear edge; a base plate having a front edge and a rear edge; wherein the base plate is secured to the lower surface of the seat and aligned such that the front edge of the base plate is adjacent to the front edge of the seat and the rear edge of the base plate is adjacent to the rear edge of the seat; a retention slot located toward the front edge of the base plate; a spring-loaded latch mechanism located toward the rear edge of the base plate; wherein the spring-loaded latch mechanism has at least one spring-loaded latch bolt; a mounting plate having a front edge and a rear edge; wherein the front edge of the mounting plate has a tab that is receivable in the retention slot of the base plate; and wherein the rear edge of the mounting plate has at least one catch opening that is configured and arranged to be received in engagement with the latching mechanism.
 2. The seat assembly of claim 1, wherein the spring-loaded latch mechanism has at least one actuator, each actuator configured to retract at least one latch bolt.
 3. The seat assembly of claim 1, wherein the spring-loaded catch mechanism has two spring-loaded latch bolts.
 4. The seat assembly of claim 3, wherein the spring-loaded latch mechanism has at least one actuator to retract the latch bolts.
 5. The seat assembly of claim 3, wherein the spring-loaded latch mechanism has two actuators, the actuators being capable of retracting the latch bolts when the actuators are moved towards each other.
 6. The seat assembly of claim 1, further comprising a center plate that is secured onto the mounting plate, wherein the center plate is capable of receiving a gas tube for controlling the height of the seat from the ground, and the spring-loaded latch mechanism does not interfere with the ability of the center plate to receive the gas tube.
 7. The seat assembly of claim 1, wherein the seat is able to recline, and wherein the seat assembly further comprises a spring that is capable of providing resistance to the seat's reclining motion and a manually accessible tension control knob for manually adjusting a coil spring in order to adjust the resistance to reclining.
 8. The seat assembly of claim 1, wherein the base plate is secured to the lower surface of the seat by a plurality of threaded fasteners.
 9. The seat assembly of claim 1, further comprising: a button on the gas cylinder; and a lever supported by the mounting plate; wherein the seat is able to recline; and wherein the lever can be rotated to depress the button on the gas cylinder and can slide longitudinally to control the ability of the seat to recline.
 10. The seat assembly of claim 1, further comprising a seat back plate for receiving a seat back, the seat back plate being secured to the center plate and the base plate so that the seat back may pivot at a different rate than the seat.
 11. The seat assembly of claim 1, further comprising a plurality of projections on the base plate and a plurality of apertures on the mounting plate, wherein the plurality of projections and the plurality of apertures are located in a corresponding manner such that when the mounting plate is secured to the base plate, the projections pass through the apertures in order to limit the ability of the base plate and mounting plate to slide against one another. 